debian/libpam0g.postinst: Handle systemd units

Debian policy now considers init scripts optional.  When booted with
systemd, use systemd facilities for determining whether a service is
enabled and restarting.  We might want to try restarting services that
are running even if disabled.  I don't think we did that in the init
script case, and I don't know a good way to determine which units
should be restarted.

* Update template description because the services are no longer
considered init scripts on most systems.  It wouldn't be worth the
translation churn alone, but we have another template change in the
same version.

* Override lintian warning regarding calling systemctl.

oops lintian

3 files changed, 45 insertions, 14 deletions

diff --git a/debian/libpam0g.lintian-overrides b/debian/libpam0g.lintian-overrides
index f66356af..5f36562d 100644
--- a/debian/libpam0g.lintian-overrides
+++ b/debian/libpam0g.lintian-overrides
@@ -6,3 +6,6 @@ libpam0g: package-name-doesnt-match-sonames libpam0 libpam-misc0 libpamc0
 # before
 libpam0g: no-debconf-config
 libpam0g: postinst-uses-db-input
+# Yes, we want to use systemctl; if the service is running we do need
+# to restart it. We have already asked the admin.
+libpam0g: maintainer-script-calls-systemctl
diff --git a/debian/libpam0g.postinst b/debian/libpam0g.postinst
index 55928557..23320c8f 100644
--- a/debian/libpam0g.postinst
+++ b/debian/libpam0g.postinst
@@ -52,7 +52,44 @@ filerc() {
     echo ""
 }
 
-installed_services() {
+if test -d /run/systemd/system; then
+    is_service_configured() {
+        systemctl is-enabled --quiet $1 || return 1
+    }
+    restart_service() {
+        if systemctl try-restart $1; then
+            :
+        else
+            failed = "$failed $1"
+        fi
+    }
+else # not systemd
+    is_service_configured() {
+	idl="/etc/init.d/${service}"
+	if [ -n "$idl" ] && [ -x $idl ]; then
+return 0
+	else
+            return 1
+        fi
+    }
+
+    restart_service() {
+        service="$1"
+	idl="invoke-rc.d ${service}"
+	echo -n "  $service: stopping..." 2>&1
+	$idl stop > /dev/null 2>&1 || true
+	sleep 1
+	echo -n "starting..." 2>&1
+	if $idl start > /dev/null 2>&1; then
+	    echo "done." 2>&1
+	else
+	    echo "FAILED! ($?)" 2>&1
+	    failed="$service $failed"
+	fi
+    }
+fi
+    
+                 installed_services() {
     check="$@"
 
     # Only get the ones that are installed, and configured
@@ -75,10 +112,10 @@ installed_services() {
 
     for service in $check; do
 	idl="/etc/init.d/${service}"
-	if [ -n "$idl" ] && [ -x $idl ]; then
+	if is_service_configured $service; then
 		services="$service $services"
 	else
-		echo "WARNING: init script for $service not found." >&2
+		echo "WARNING:  $service not configured." >&2
 	fi
     done
     echo "$services"
@@ -152,16 +189,7 @@ then
 				continue
 			    ;;
 			esac
-			echo -n "  $service: stopping..."
-			$idl stop > /dev/null 2>&1 || true
-			sleep 1
-			echo -n "starting..."
-			if $idl start > /dev/null 2>&1; then
-			    echo "done."
-			else
-			    echo "FAILED! ($?)"
-			    failed="$service $failed"
-			fi
+                        restart_service "$service"
 		    done
 		    echo
 		    if [ -n "$failed" ]; then
diff --git a/debian/libpam0g.templates b/debian/libpam0g.templates
index 64a616ac..6026ee73 100644
--- a/debian/libpam0g.templates
+++ b/debian/libpam0g.templates
@@ -3,7 +3,7 @@ Type: string
 _Description: Services to restart for PAM library upgrade:
  Most services that use PAM need to be restarted to use modules built for
  this new version of libpam.  Please review the following space-separated
- list of init.d scripts for services to be restarted now, and correct it
+ list of  services to be restarted now, and correct it
  if needed.
 
 Template: libpam0g/xdm-needs-restart